Lathe-dog.



c. 1). ANDREW.

LATHE DOG.

APPLICATION FILED JUNE 30,1013.

Patented Aug. 18, 19%

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WASHINGTON, u I:

III MORRIS PETERS CO.. PHO

CECIL DANIEL ANDREW, OF MANCHESTER, ENGLAND.

LATHE-DOG.

Specification of Letters latent.

Patented Aug. 18, 1914..

Application filed June 30, 1913. Serial No. 776,502.

To all whom it may concern Be it known that I, CECIL DANIEL AN- DREW, of Manchester, in the county of Lancaster, England, have invented certain new and useful Improvements in Lathe-Dogs, of which the following is a specification.

This invention relates to lathes and similar machine tools but more particularly to those classes of lathes known as railway wheel lathes.

In railway wheel turning lathes it' is usual to employ a number of drivers or dogs which by gripping contact hold the wheel in the operative working position. An essential feature of such dogs is a movable member, having an outer face suitably serrated, which can be adjusted to impinge against the wheel being dealt with and thus hold it in position as stated. Hitherto each of the series of dogs employed to hold a wheel in position have been adjusted individually when being brought into a holding position with the result that in many cases the wheel has been forced out of true, although the amount of such deviation may be comparatively slight. This has been aided by the fact that in many instances the face of the work itself is not originally true. The cut is taken while the wheel is in this distorted condition as there are no means for accurately ascertaining whether the pres sure on the wheel is alike at all points. The result of this is that when taken from the machine the wheels do not spin true and must be dealt with again.

The object of the present invention is to obtain a uniform automatic pressure and provide means whereby railway wheels, or other work, may be accurately held in the lathe by the adjustment of one or more dogs which react on the remaining dogs.

The invention comprises pivotal members connected to or bearing on the dogs of railway wheel or like lathes supported in such a manner that they possess balancing or compensating quality to the extent that the adjustment of one dog will automatically bring about an adjustment of the other dogs and insure an equal pressure upon the face of the work. It should be understood that the dogs carried on one face plate are quite distinct from those carried on the other face late. p A sheet of drawings is appended whereon Figure 1 is a front elevation of a face plate carrying my invention. Fig. 2 is a view looking in the direction of the arrow in Fig. l and Fig. 3 is a side elevation of Fig. 1.

In the form of construct-ion shown a pair of beams A A are employed which at their outer ends A A bear against the lower ends'of dogs B, B, B B These dogs are carried in brackets C, C, C C suitably attached to the face plate D and if necessary they can be so attached as to permit ready tangential or radial adjustment. The beams A, A are pivotally supported at their centers on project-ions or the like A attached to or formed as part of the frame E. The frame E is pivotally carried in bearings or suitable brackets F F attached to the face plate D and can oscillate in a direction at right angles to the direction of movement of the beam A A.

The dog B is threaded as shown in Fig. 3 and is provided with a hexagon portion H, and the plunger P is threaded internally and fitted with a key, so that when the hexagon portion H is rotated it causes the dog to move toward or away from the face plate D.

The action of tightening up or applying pressure to any particular dog or dogs automatically causes a re-action of the pressure upon the other dogs which of course impinge at other points upon the face of the work to be done. The pressure is communlcated in the case of the adjustment of B through A to B. Both dogs then re-act through A on to E which pivots on its pivots E E and operates the beam A which reacts upon the dogs B B The result is to produce a compensating or equalizing effect and to insure an equal pressure on the face of the work by the dogs B, B, B B

When the dogs are in their holding position the brackets C, C, C G which support the said dogs bear the load of the drive and thus prevent distortion of the beams A A or the frame E.

This invention may have several applications for different classes of work and the details may be modified so that it can be applied to various different types of machine tool. I.

Claims.

1. In a turning lathe, a device for engaging with and driving the work comprising a face plate, a frame pivotally mounted upon the face plate, dogs adapted to engage with the work, and means whereby'the said dogs may receive movement in a direction mally to the face plate.

3. In a turning lathe, a device for engaging with androtating the work comprising a face plate, a rocking member mounted upon the face plate, dogs adapted to engage with the work and mounted upon the face plate, and dog-actuating members mounted upon the frame and adapted to rock about axes situated transversely of the axis about which the frame rocks.

4. In a turning lathe, a work-engaging device comprising dogs arranged in pairs, guides for the said dogs, a face plate sup porting the said guides, a rocking frame mounted upon the face plate, and beams the opposite ends of each of which act'upon each pair of dogs, each of the said beams being adapted to rock about an axis situated transversely of the axis of the'rocking frame.

5. In a turning lathe, a work-engaging device comprising a number of dogs, rock mg means for actuating the said dogs, and a rocklng support for the dog-actuating means the axis of the said support being arranged transversely of the axis of the dogactuatmg means. i

6. In a turning lathe, a work-engaging 'device comprising two pairs of dogs adaptoted the axis of the said frames being arranged transversely of the axis of the beams.

7. In a turning lathe, a work-engaging device comprising a face plate, fixed sockets mounted upon the said plate, pairs of dogs each adapted to slide within one of the said sockets, a frame pivoted upon the face plate, and beams pivoted upon the frame the op posite ends of each of the said beams being adapted to engage with the dogs of each pair and the axis of the beamsbeing situated transversely of the axis of the frame.

8. In a turning lathe a w0rk-carrying device comprising a face plate, a rocking frame mounted upon the face plate, dogs adapted to engage with the work and pivoted connecting means between the face plate and the dogs whereby the adjustment of one dog automatically brings about an adjustment of the other dogs in a direction normal to the face plate.

In testimony whereof I have affixed my signature in presence of two Witnesses.

CECIL DANIEL ANDR-Elv.

Witnesses:

FRANCIS IVILLIAM BARRACLOUGI-I, FRANTZ NASMITH.

Copies of this patent may be fobtained for five cents eaeh,-by addressing the Commissioner of Patents, Washington, D. G. 

